#include <cstdio>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <set>
#include <vector>

using std::cin;
using std::cout;

using i64 = long long;
using pii = std::pair<int, int>;

const int nx = 1e5;

int tc;

int n;
int a[nx + 5], b[nx + 5];

int m;
int x[nx + 5], t[nx + 5];
int pv[nx + 5];
std::vector<int> v[nx + 5];

std::set<pii> st;

int main() {
    std::ios::sync_with_stdio(false);

    cin >> tc;
    while (tc--) {
        cin >> n >> m;
        for (int i = 1; i <= n; ++i) {
            cin >> a[i];
            v[i].clear();
            pv[i] = 0;
        }
        for (int i = 1; i <= m; ++i) {
            cin >> x[i] >> t[i];
        }
        i64 res = 0, sum = 0, ans = 0;
        for (int i = 1; i <= n; ++i) sum += a[i], b[i] = a[i];
        for (int i = 1; i <= m; ++i) {
            res += x[i] - x[i - 1];
            if (sum >= res) {
                if (b[t[i]] >= res) sum = sum - b[t[i]] + a[t[i]], b[t[i]] = a[t[i]], res = 0;
                else sum = sum - b[t[i]] + a[t[i]], res -= b[t[i]], b[t[i]] = a[t[i]];
            }else {
                ans = x[i - 1] + sum - (res - x[i] + x[i - 1]);
                break;
            }
        }
        if (ans == 0) ans = x[m] + sum - res;
        cout << ans << '\n';
    }
    return 0;
}